No matter how fairy or pretty your design / template is, never use overflow:hidden for content containers.
Content comes a thousand times more important than any design or layout. I don’t care how much you hold proud your artistic work and how you think accommodating the content in any way possible would ruin the holy sweet layout, when an image or a table with indispensable content that the readers / visitors are ultimately concerned about expands across the content areas and messing up with your fucking design, using overflow:hidden to restrict them is just plain STUPID and ANNOYING.
Please by all means, DO NOT use overflow:hidden for content containers! What really matters is the idea / content the design is trying to convey rather than the design itself.